Overlord

Overlord is a general purpose device monitoring and proxying framework.

Overlord provides a web interface which allows you to access device you have control of directly on the web. Features include:

1. shell access
2. file transfer
3. port forwarding
4. webcam streaming(directly from the web)
5. VPN(to be implemented)

and more. A CLI tool is also provided for accesing the connected clients. The Overlord server serve as a proxy, which means the devices are still accessible even if they are behind a NAT.

Opening terminals directly on the web-based dashboard

File upload via drag and drop

File download directly with HTTP download

Build

Run make in the project root directory. make builds the overlord daemon and the go version of the ghost (overlord client). The resulting binary can be found in the bin directory. Note that You need to have the Go compiler installed on your system.

Basic Deployment

1. On a server with public IP (to be used as a proxy), run overlordd -port 9000 to start the server (if -port is not specified, default port is 80 or 443 depends on whether TLS is enabled or not).
2. On a client machine, run ghost SERVER_IP or ghost.py SERVER_IP. ghost and ghost.py are functional equivalent except one is written in Python, and the other is written in Go.
3. Browse http://SERVER_IP:9000 and you will see the overlord web dashboard. The default user/password is overlord/cros. To change the password, please follow the Overlord advanced deployment guide.

For testing purpose, you can run both server and client on the same machine, then browse http://localhost:9000 instead. If you want to disable authentication of the web dashboard, you could add the -noauth option when starting overlordd. Overlord server supports a lot of features such as TLS encryption, client auto upgrade. For setting up these, please refer to the Overlord advanced deployment guide.

Usage

Overlord provides a web interface for interacting with the devices connected to it. The Overlord server provides a set of APIs that can be used for creating different apps(views) according to the need. The default dashboard provides an app-switcher on the top right corner.

Besides from the web interface, a command line interface is also provided. The ovl command (located at scripts/ovl.py) not only provides the same functionality to the web interface but also provide command line only functions such as port forwarding and VPN (to be implemented). The basic usage is as follows:

1. Connect to the overlord server

$ ovl connect SOME_SERVER_IP 9000
connect: Unauthorized: no authorization request
Username: user
Password:
connection to SOME_SERVER_IP:9000 established.

2. List connected clients

$ ovl ls
client1
client2
client3

3. Select default target to operate on

$ ovl select
Select from the following clients:
    1. client1
    2. client2
    3. client3

Selection: 1

4. Open a shell

$ ovl shell
localhost ~ # _

5. File transfer

% ovl push test_file /tmp
test_file                   9.9 KiB   38.1K/s 00:00 [#####################] 100%
% ovl pull /tmp/test_file test_file2
test_file                   9.9 KiB    1.1M/s 00:00 [#####################] 100%

6. Port forwarding: forward the port on client to localhost (assuming we have a web server running on client1's port 80)

% ovl forward 80 9000
% ovl forward --list
Client   Remote    Local
client1  80        9000
% wget 'http://localhost:9000'
--2016-03-08 17:56:59--  http://localhost:9000/
Resolving localhost... ::1, 127.0.0.1
Connecting to localhost|::1|:9000... failed: Connection refused.
Connecting to localhost|127.0.0.1|:9000... connected.
HTTP request sent, awaiting response... 200 OK
Length: 419 [text/html]
Saving to: ‘index.html’

index.html          100%[===================>]     419  --.-KB/s    in 0s

2016-03-08 17:57:00 (37.5 MB/s) - ‘index.html’ saved [419/419]

Disclaimer

The Overlord project originates from the Chromium OS factory repository, which is used for monitoring and deploying test fixtures in a factory. The implementation of Overlord is general enough for non-factory use, thus, it's put into this GitHub mirror for greater visibility. All source code in this repository belongs to the Chromium OS project and the source code is distributed under the same license.